We investigated the changes of signs and symptoms in 18 cases suffering from persistent closed lock.
The results were as follows:
1. Severe pain was present in all patients at the beginning of treatment. At the end of treatment, severe pain was noted in only one patient. Pain disappeared or improved in the other patients. Continued improvement was found during follow-up.
2. Average maximum mouth opening was increased from 25.2 mm to 35.3 mm after conservative treatment. This trend also continued during follow-up (ave. 37.3 mm).
3. Crepitation was noted in 44.4% of the patients at first visit. It increased during conservative treatment, and was noted in 77.8% at the end of treatment. However, crepitation decreased, and was recognized in 55. 6% during follow-up.
4. The incidence of radiographic bone changes (erosion, osteophytes and/or deformity) of the condylar head was 66.7% initially and increased during treatment and follow-up.
5. These results indicate that severe pain and trismus in these patients improved to some degree by long-term conservative treatment, but prolonged careful follow-up is required in persistent cases, especially those with bone changes and/or crepitation.